In the production and stimulation of oil and gas wells, special flow control tools, such as cement retainers and bridge plugs, must be set downhole. These flow control tools are set at the desired depth within the well using a setting tool. The setting tools are normally activated hydraulically, mechanically or by wireline. In deviated holes, hydraulic or wireline activated setting tools are generally preferred. In other wells, where the hole is not deviated as to preclude the mechanical setting of the flow control tool, a mechanical setting tool may be preferred. This is particularly the case where shallow depths are involved.
Past mechanical setting tools, while used for many years, had been overly complex and susceptible to premature setting. For example, in setting a flow control tool mechanically, the tool is mounted to the mechanical setting tool which is lowered into the well casing on the end of the pipe string. The setting tool is normally actuate by rotating the pipe string to actuate control mechanisms on the setting tool and by picking up and lowering the pipe string to further actuate the setting tool to set the flow control tool. Great care must be exercised to prevent premature setting of the tool. In fact, a primary problem with mechanical setting tools is the problem occasioned by premature setting, which results in the flow control tool being set at the incorrect depth. Such "misfires" require the drilling out the flow control tool which results in substantial loss to the operator.
Prior setting tools have also been extremely complex in their design and require a sequence of steps for actuation. Such sequence may be easily confused and is generally difficult to follow, causing the unsuccessful use of the setting tool in many cases. Further, many of the tools require auxiliary slips which are incorporated on the flow control tool. Generally, the flow control tool which is mechanically set is different in design from that which is to be hydraulically set. Thus, two separate flow control tools must be maintained on-hand, depending upon the method of setting.
Thus, a need exists for a mechanical setting tool which effectively eliminates the possibility of premature setting while running the setting tool in the well. Further, the need exists for a setting tool which can be easily actuated and removed subsequent to setting of the flow control tool.